Pharmacy and medicine have discovered the use of dosage forms are increasingly important in the administration of drugs for better health. The dosage forms often provide improved patient compliance accompanied by better control of drug blood levels, reliable and reproducible drug-release profiles, and frequently a reduced coat of therapy.
In the past however, serious short comings were associated with the administration of drugs. For example, the dosage form did not mask an unpleasant taste, or the dosage form did not improve the stability of a drug formulation, or the dosage form did not prevent oxidation of a drug. Then too, materials used to manufacture a coat that enveloped a drug in a dosage form can abstract from the dosage form. For example, coatings made from carbohydrates are water-soluble, they readily disintegrate and give rise to noncontrolled dose dumping of a drug, or a coating made from an enteric phthalate pass intact through the stomach but undergo disintegration in the intestinal tract, or alkylcellulosic polymers such as ethylcellulose exposed to the gastrointestinal tract are lipophilic and absorb endogenous fats and consequently evidence a lack of structural integrity as seen in flaws or cracks in the coat; also, they can become impermeable to aqueous fluids including water and biological fluids to the extent they become nonfunctional for membrane-controlled delivery mechanisms.
It is clear from the above presentation that a long-felt need exists for a dosage form comprising a coat thereon for orally administering a drug at a controlled and sustained-release drug delivery profile with time. The need exists for a dosage form for administering a drug in a linear profile for cardiovascular, arthritic, respiratory, cancer, analgesic and other therapies. A dosage form is needed for replacing immediate-release dose-dumping form administered three or four times daily. There are reasons for seeking a dosage form that replaces immediate-release forms including a means for reducing peak blood levels followed by a sharp drop in blood levels, a means for lessening side effects, a means for maintaining the structural integrity of the dosage form, and a means for reducing the number of solvents to manufacture the dosage form.